The Bloomberg administration is going to oppose a bill that could put buyers of fake luxury products behind bars, The Post has learned.

The bill — first proposed two years ago by City Councilwoman Margaret Chin (D-Manhattan) — is finally getting its first hearing today.

In addition to jail time of up to a year, bargain hunters ready to buy a “Rolex” from a furtive guy in an alley would face a $1,000 fine.

“It’s such a large fine it would deter people from making nearly any purchases,” said one source, explaining the administration’s opposition.

Images of wide-eyed tourists being hauled off by cops also wouldn’t sit well at City Hall.

But Chin argued that drastic measures are necessary because the counterfeit trade continues to thrive in Chinatown, which she represents, despite raids where truckloads of fake goods are routinely seized.

“What we’re trying to do is cut down on the demand,” she said.

“We really have to put a stop to this.”

Chin scoffed at the possibility that some naive buyers might not realize they’re engaging in a criminal transaction.

“If you’re buying something off the street, paying cash, doing it in a sneaky way, c’mon,” she said.

Councilman Peter Vallone (D-Queens), who chairs the Public Safety Committee, delayed giving it a hearing because he said he had doubts about the tough penalties.

He said he was eventually convinced by a persistent Chin that something had to be done.

“I don’t support subjecting buyers to a year in jail,” he said. “Other penalties we can look at.”

He agreed that buyers who plunk down $50 for a Louis Vuitton handbag that normally commands a four-figure price know full well they’re gaming the system.

“You don’t have unknowing buyers any more,” said Vallone, mentioning that transactions often involve shady characters in back alleys. “It’s more like a hostage exchange.”